Lubricant for commutators.



. hour or more.

UNITED STATES PATENT tries.

\VILLIAM M. JONES, OF SAN FRANCISCO, CALIFORNIA.

LUBRICANT FOR COMMUTATORS.

SPECIFICATION formingpart of Letters Patent No. 680,155, dated August 6,1901.

' Application filed January 7, 1901. Serial No. 42,424. (Np specimens.)

To all whom it may concern.-

Be it known that I, VVILLIAM M. JONES, a citizen of the United States,residing at San Francisco, in the county of San Francisco and State ofCalifornia, haveinvented certain new and useful Improvements inLubricants for Oommutators, of which the following is a specification.

My invention relates to improvements in lubricating compounds moreespecially intended for use on commutators, the object of my inventionbeing to provide a commutator compound which will prevent sparking atthe brushes and will also prevent the cutting of the brushes andcommutator-s.

In preparing this compound I take five pounds of paraffin-wax and threepounds of graphite and boil them together for about one hour and a halfat a very high temperature. I have not been able to ascertain the degreeof such temperature; but it is as high a temperature as is possiblewithout burning. In other words, the temperature must be maintainedbelow that of spontaneous ignition. I find that during the process ofboil ing a heavy black smoke is given ofi for an The mixture then boilsquite colorless without giving off any smoky vapor, and after boilingclear for fifteen or twenty minutes the boiling is stopped. It is foundthat the volume of the material has diminished quite an appreciableextent during the boiling. After the mixture has cooled a trifle I addabout one teaspoonful of spermaceti. The mixture is then cooled in moldsin the form of sticks of suitable size and shape for the purposedesired.

In my experiments to provide a compound which will prevent sparks Ifound that p31 affin and graphite if mixed together without boiling makea plastic compound which lubricates the commutator, but creates a greatdeal of sparking at the brushes. This sparking is no doubt due to thesubstance which is given off in the form of heavy black smoke, beforereferred to, for I find that after this substance has been removed thereis practi cally no sparking except that which is occasioned by pits orother defects in the 001m mutators. I have also found that if themixture so boiled be cooled without the addition of the spermaceti thecompound when solidified is no longer plastic, but is very brittle, andindeed has so little adhesiveness that it will not stay on thecommutator. The addition of the small quantity of spermaceti gives itsufficient adhesiveness to enable it to stick to the commutator. Thelubricant will be found to color the commutator a light walnut color,and the surface of the commutator will be polished.

I claim- A solid lubricant comprising paraffin and graphite insubstantially the proportions specified, which has been boiled at a hightemperature until the vapor driven off is perfectly colorless, to whicha small quantity of spermaceti has been added after boiling and beforecooling, substantially as described.

In witness whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

W. M. JONES.

Witnesses:

FRANCIS M. WRIGHT, K. LOCKWOOD NEVINS.

